In order to produce hydrocarbons from within a subterranean formation, a wellbore is drilled, penetrating the subterranean formation. This provides a partial flow path for hydrocarbon, received by the wellbore, to be conducted to the surface. In order to be received by the wellbore at a sufficiently desirable rate, there must exist a sufficiently unimpeded flow path from the hydrocarbon-bearing formation to the wellbore through which the hydrocarbon may be conducted to the wellbore.
In some cases, in order to establish the flow path for conducting the hydrocarbon to the wellbore, it is necessary to create new fractures or extend existing fractures within the subterranean formation. Such fractures are more permeable to the flow of hydrocarbons than the formation.
To initiate new fractures, hydraulic fracturing fluid is injected through wellbore into the subterranean formation at sufficient rates and pressures for the purpose of hydrocarbon production. The fracturing fluid injection rate exceeds the filtration rate into the formation producing increasing hydraulic pressure at the sand face. When the pressure exceeds a critical value (the fracture initiation pressure), the formation rock cracks and fractures.
The induced fractures are often interconnected with existing naturally occurring fractures. Often, the permeability of such naturally occurring fractures is relatively low.